Sensor devices are used in a variety of applications. For example, sensor devices are used for energy management. In such a case, the sensor device can be placed in a space (e.g., a room) and can measure one or more of a number of parameters within the space. Such parameters can include, but are not limited to, an amount of ambient light and movement. Thus, a sensor device can include one or more of a number of sensors that read some form of signal (e.g., light waves). Examples of sensors that are included in a sensor device can include, but are not limited to, a photo sensor, a light sensor, and an infrared detector. In addition, a sensor device can include one or more of a number of other components. For example, a sensor device can include an indicating light to let a user know whether the sensor device is operating properly. As a result, one or more light sources can be co-located, along with a light sensor, in a sensor device.